Medical devices can be inserted into patients percutaneously. Generally, medical devices have a low profile for minimally invasive introduction. However, such low profile design can inhibit the functionality of medical devices. For example, it may be advantageous for a catheter to assume a configuration having a profile larger than the needle, introducer, or guide catheter through which the medical device was introduced. Traditionally, such enlargement in profile has been accomplished by inflation of a balloon mounted on a catheter. However, use of balloons for expansion has limitations. Balloons have difficulty in creating fine or complex shapes. Balloons typically fully occlude passageways even if full occlusion is not wanted. Balloons lack precision in the degree of expansion. It can be difficult to develop sufficient hydraulic pressure through an inflation lumen being that the inflation lumens are narrow and long, two factors that contribute to pressure drop. Balloons are conventionally employed on catheters which extend ex vivo but are not typically used in fully implantable devices. Various embodiments of the present disclosure overcome these and/or other limitations of having expansion and/or contraction functionality that is not controlled by inflation of a balloon.